A stone is dropped from the top of a 250 m tower. (Acceleration due to gravity is -9.8 m/s2. Ignore air resistance. Give your answers correct to two decimal places.)
(a) Find the distance of the stone above ground level at time t.
(b) How long does it take the stone to reach the ground?
(c) With what speed does it strike the ground?
(d) If the stone is thrown downward with a speed of 8 m/s, how long does it take to reach the ground?